基于RS和SWMM的海河干流中游典型区域降雨径流污染解析

发布时间：2018-09-11 14:09

【摘要】：海河是我国七大水系之一,也是华北地区的第一大水系,其干流主要流经天津市区和滨海新区,最终在大沽口汇入渤海。海河流域在我国十大流域中污染最为严重,水环境质量差、污染压力大、环境风险高。在海河干流中游区域,由于工业园区集中、支流环境复杂,复合污染特征十分明显。空港经济区作为海河干流中游段的典型区域,其排污与暴雨径流等面源污染对海河及其支流水系形成了严重的混合污染,探究经济区内暴雨径流造成的面源径流污染,从而针对性地研发径流污染控制技术,能有效降低海河干流中游水系的污染负荷。本文利用GIS和RS技术提取研究区下垫面类型,并分析了不同下垫面径流污染特性,在此基础上建立研究区SWMM模型,探究研究区暴雨径流及径流污染状况,主要研究内容及结论为:首先,基于RS和GIS技术,利用WorldView-II高分辨率遥感影像对研究区下垫面类型进行提取。结合模型需求及研究区实际情况,选取了绿地、不透水花砖和其他类型作为空港经济区的主要下垫面类型。其次,分析不同下垫面的径流污染物输出特征。利用模拟降雨装置模拟降雨,分别检测流经三种下垫面的雨水径流及污染物释放情况,得到COD、TN和TP的EMC值。从单一下垫面在降雨径流中的污染物浓度来看,流经绿地的雨水径流中TP浓度显著高于其他下垫面。最后,建立研究区SWMM模型,进行雨水径流模拟。由于本文研究区域范围较大,降雨开始后45分钟雨水排放口才开始出现径流,径流持续时间达十小时以上。整个降雨过程入渗量较大,说明该区域透水性较好,绿地面积比例较大。污染物在径流初期迅速增长,降雨历时2小时左右达到峰值。三种污染物的变化趋势一致,峰值较高,污染比较严重。从径流水质评价结果来看,峰值期各排放口污染均比较严重,而从整场降雨造成的污染物平均值来看,三种污染物超标最严重的是COD,TP污染状况相对较轻。各排放口径流量和污染物在不同重现期降雨情景下的变化趋势基本一致,重现期越大,径流量越大,径流污染越严重。
[Abstract]:Haihe River is one of the seven major water systems in China and the largest in North China. Its main stream flows mainly through Tianjin City and Binhai New area and eventually flows into the Bohai Sea at the mouth of Dagu. Haihe River Basin is the most serious pollution in the ten watersheds in China, the water environment quality is poor, the pollution pressure is high, and the environmental risk is high. In the middle reaches of the main stream of Haihe River, because of the concentration of industrial park and the complex environment of tributaries, the characteristics of complex pollution are very obvious. As a typical area in the middle reaches of the main stream of the Haihe River, the pollution of non-point sources such as sewerage and rainstorm runoff has caused serious mixed pollution to the Haihe River and its tributaries, and the non-point source runoff pollution caused by the torrential rain runoff in the economic zone has been explored. Therefore, the research and development of runoff pollution control technology can effectively reduce the pollution load in the middle reaches of the main stream of Haihe River. In this paper, GIS and RS techniques are used to extract the underlying surface types of the study area, and the characteristics of runoff pollution in different subsurface runoff are analyzed. On the basis of this, the SWMM model of the study area is established to explore the rainstorm runoff and runoff pollution in the study area. The main contents and conclusions are as follows: firstly, based on RS and GIS techniques, the type of underlying surface in the study area is extracted by using WorldView-II high-resolution remote sensing images. According to the demand of the model and the actual situation of the research area, green space, impermeable tile and other types are selected as the main underlying surface types of the airport economic zone. Secondly, the characteristics of runoff pollutant output from different underlying surfaces are analyzed. The simulated rainfall device was used to simulate rainfall. Rain Water runoff and pollutant release through three underlying surfaces were detected respectively, and the EMC values of COD,TN and TP were obtained. According to the concentration of pollutants in rainfall runoff, the concentration of TP in the runoff of Rain Water flowing through green space is significantly higher than that of other underlying surfaces. Finally, the SWMM model of the study area was established to simulate Rain Water runoff. Because of the large area in this paper, after 45 minutes of rainfall, Rain Water began to produce runoff, and the runoff lasted more than 10 hours. The infiltration amount of the whole rainfall process is large, which indicates that the area of this area is better in water permeability and the proportion of green space area is larger. The pollutant increased rapidly in the initial stage of runoff, and the rainfall lasted about 2 hours to reach the peak. The change trend of the three pollutants is the same, the peak value is higher and the pollution is more serious. According to the results of runoff water quality evaluation, the pollution of each discharge port in peak period is very serious, but from the average value of pollutants caused by the whole rainfall, the most serious pollution of three kinds of pollutants is that the COD,TP pollution is relatively light. The variation trend of discharge calibre and pollutant is basically the same under rainfall scenarios in different recurrence periods. The larger the recurrence period, the larger the runoff and the more serious the runoff pollution is.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X52

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